Enum ConstantExprKind 

pub enum ConstantExprKind<'tcx> {
    Literal(ConstantLiteral),
    Adt {
        kind: VariantKind,
        fields: Vec<ConstantFieldExpr<'tcx>>,
    },
    Array {
        fields: Vec<ConstantExpr<'tcx>>,
    },
    Repeat {
        value: ConstantExpr<'tcx>,
    },
    Tuple {
        fields: Vec<ConstantExpr<'tcx>>,
    },
    NamedGlobal(ItemRef<'tcx>),
    Ptr {
        base: ConstantPtrBase<'tcx>,
        projections: Vec<(ConstantProjectionElem<'tcx>, Ty<'tcx>)>,
        metadata: Option<UnsizingMetadata<'tcx>>,
    },
    PtrCast(ConstantExpr<'tcx>, Option<UnsizingMetadata<'tcx>>),
    ConstRef {
        id: ParamConst,
    },
    FnDef(ItemRef<'tcx>),
    FnPtr(FnPtrTarget<'tcx>),
    TypeId(Ty<'tcx>),
    Memory(Vec<ConstantByte<'tcx>>),
    Todo(String),
}

The subset of expressions that corresponds to constants.

Variants

Literal(ConstantLiteral)

Adt

Fields

kind: VariantKind

fields: Vec<ConstantFieldExpr<'tcx>>

Array

Fields

fields: Vec<ConstantExpr<'tcx>>

Repeat

Fields

value: ConstantExpr<'tcx>

Tuple

Fields

fields: Vec<ConstantExpr<'tcx>>

NamedGlobal(ItemRef<'tcx>)

A top-level or associated constant.

Remark: constants can have generic parameters. Example:

struct V<const N: usize, T> {
  x: [T; N],
}

impl<const N: usize, T> V<N, T> {
  const LEN: usize = N; // This has generics <N, T>
}

impl Foo for Bar {
  const C : usize = 32; // <-
}

If options.inline_anon_consts is false, this is also used for inline const blocks and advanced const generics expressions.

Ptr

A reference or raw pointer (as given by the type of this constant) to a place inside a constant value: projections applied to base, each with the type of the place it reaches.

Fields

base: ConstantPtrBase<'tcx>

projections: Vec<(ConstantProjectionElem<'tcx>, Ty<'tcx>)>

metadata: Option<UnsizingMetadata<'tcx>>

PtrCast(ConstantExpr<'tcx>, Option<UnsizingMetadata<'tcx>>)

Casts a thin pointer to the type of this constant. If metadata is given, this is an unsizing cast from the pointee of the given pointer.

ConstRef

Fields

id: ParamConst

FnDef(ItemRef<'tcx>)

A function definition, corresponding to a particular item. This is a ZST, unlike FnPtr.

FnPtr(FnPtrTarget<'tcx>)

A function pointer. This is an actual pointer to that function.

TypeId(Ty<'tcx>)

The TypeId of this type.

Memory(Vec<ConstantByte<'tcx>>)

A blob of memory containing the byte representation of the value. This can occur when evaluating MIR constants (e.g. unions). Interpreting this back to a structured value is left as an exercice to the consumer.

Todo(String)

Trait Implementations

impl<'tcx> Clone for ConstantExprKind<'tcx>

fn clone(&self) -> ConstantExprKind<'tcx>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'tcx> Debug for ConstantExprKind<'tcx>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'tcx> Eq for ConstantExprKind<'tcx>

impl<'tcx> Hash for ConstantExprKind<'tcx>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'tcx> PartialEq for ConstantExprKind<'tcx>

fn eq(&self, other: &ConstantExprKind<'tcx>) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<'tcx> StructuralPartialEq for ConstantExprKind<'tcx>